Hospitalists, dedicated inpatient physicians, provide care for patients from hospital admission to discharge. The growing popularity of hospitalists is based on their potential to provide better inpatient health care value compared with traditional PCPs. One survey of hospitalists (Lindenauer et al., 199) and four outcome studies (Craig, 199; Diamond, 1998; Stein, et al., 1998; Wachter et al., 1998) have been published in peer-reviewed journals, but one of these efforts provides a detailed examination of differences in the characteristics and inpatient practices of hospitalists and traditional PCPs. The current proposal will use established qualitative and quantitative methods to develop a telephone survey instrument to assess the characteristics and inpatient practices of hospitalists and traditional PCPs. The long-term objective of this proposal is to implement the survey in a national sample of hospitalists and traditional PCPs to establish key physician characteristics and practices that may be linked to national data on quality of care, cost, and outcomes of hospitalized patients. The survey will be developed in collaboration with the ACP-ASIM, the NAIP, and the AAFP, using in-house researchers and accessing membership lists for a pilot sample. Items will be evaluated through focus groups and cognitive interviews with hospitalist and traditional internal medicine and family practice physicians. The survey will be piloted on a sample of 50 traditional internal medicine and family practice physicians and 50 hospitalists randomly selected from the membership lists of the above organizations. The specific aims of the professional practice behaviors of internal medicine physicians and family practice physicians practicing either as hospitalists or as traditional PCPs, (2) Evaluate the reliability and validity of the survey for use in a large national survey of hospitalist and traditional physician practices, and (3) Identify differences between hospitalists and traditional PCPs in physician characteristics and practices that may lead to variations that may lead to variations in the quality, cost, and outcomes of patients.